1. Field of the Invention
The present invention relates to a nonaqueous secondary battery having a high energy density, a small self-discharge ratio, a long cycle life and a good charge-discharge efficiency (Coulomb efficiency).
2. Description of the Related Art
A polymer battery comprising an electrode composed of a polymeric compound having a conjugated double bond in the main chain is known as a secondary battery having a high energy density. Various reports concerning secondary batteries have been published, for example, by P. J. Nigrey et al, J. Chem. Soc. Chem. Commun., 1979, 594; J. Electrochem. Soc., 1981, 1651; and Japanese Unexamined Patent Publications No. 56-136,469, No. 57-121,168, No. 59-3,870, No. 59-3,872, No. 59-3,873, No. 59-196,566, No. 196,573, No. 59-203,368, and No. 59-203,369.
The use of polyaniline obtained by electrolytic oxidative polymerization of aniline as an electrode of an aqueous solution type or nonaqueous solvent type battery has already been proposed [A. G. MacDiarmid et al, Polymer Preprints, 25, No. 2, 248 (1984), Sasaki et al, Lectures at 50th General Meeting of Electrochemical Association, 123 (1983) and Sasaki et al, Lectures at 51st General Meeting of Electrochemical Association, 228, (1984)].
However, none of the known polymer batteries comprising a polymer can simultaneously satisfy all of the requirements of (i) a high energy density, (ii) a low self-discharge ratio, (iii) a high charge-discharge efficiency, and (iv) a long cycle life.